4 : UNITED STATES AND MEXICAN BOUNDARY. 
Var. 8. Greet: major, tuberculis globoso-ovatis paullo majoribus ; aculeis rigidis 2-3-seri- 
atis, interioribus 5-7 brevioribus robustioribus, exterioribus 15-18 paullo longioribus, omnibus 
radiantibus ; seminibus paullo minoribus leviter verrucosis. (Tab. II, fig. 5-8.) 
From El Paso to the San Pedro river, also in a single locality east of this river, in naked 
places on mountain-tops or sides, only on limestone, never in the porphyritic region, C. 
Wright. Var. 8. was collected by the late Dr. J. Gregg on a mountain-ridge between Azu- 
frora and Penos Bravos, near Saltillo, Mexico.—Small globose plants, depressed at top, simple, 
or very rarely (and probably only after an injury to the top of the main plant) branching ; heads 
usually 4 to 1 inch in diameter, in largest specimens seen 15-18 lines in diameter ; plants 
densely covered by the delicate ashy-grey spines ; tubercles about 4 line long, only 1-14 lines 
distant from one another ; older ones shedding the spines, and giving the base of the plant a very 
pretty tuberculated appearance ; in the larger plants 21 or 34 spiral rows of the tubercles are 
the most distinct ; spines not pungent, in several series, usually about one line long; .on the 
younger tubercles-of the fully-developed plant, (those I suppose-which may bear flowers in their 
axils,) the 6-8 upper exterior spines are 2-3, or sometimes even 4 times as long as the other 
spines, (2-4 lines long,) thickened or clavate towards the end, with an acute point; these 
spines are the first to appear in the nascent tubercle, (as indeed is the case in all Mamillarie 
where the uppermost radial spines are always developed before the others,) mixed with loose 
wool of almost the same length. These elongated superior spines form a small tuft in the vertex 
of the plant, which includes and partly hides the flowers and fruit. When they get older, 
apparently after the second or third year, the upper part of these long spines breaks off, leav- 
ing them of the same length as the others, but always distinguishable by their ragged end. 
These peculiar spines, of which I have not seen any analogy in other species, are wanting in 
younger plants. 
The position of the flowers in this plant is rather a doubtful one. I have not seen living 
specimens in flower, but the structure of the tuft, the position of the berries in the dead speci- 
mens before me, and the note of Mr. Wright, ‘flowers central’’ would -seem to indicate that 
they really appear in the new growth of the same season. In that case this species would be 
an anomalous small flowered and small tubercled Coryphantha. But I am yet anclined to con- 
sider the flowers as only nearly central, and borne in the axils of the last tubercles of the pre- 
ceding season; all the analogies at least are in favor of our plant being a true Vamillaria. 
Flowers reduced to the simplest type of Cactacee, viz: 3-5 sepals, about 5 petals, two or three 
times as many stamens, and a style with 3 stigmata; diameter of flower about 3 lines ; 
petals whitish or very light pink ; fruit an elongated clavate red and somewhat juicy berry, 4-6 
lines in length, without the remains of the flower on top, somewhat persistent on the plant, 
finally pitta up, obovate; grey, and hid in the tuft ; so it is found in the specimens brought 
home. Seeds only 6-12 in each fruit, comparatively large. 0.7 li in di i 
a very large umbilicus; testa hard ride une pai = alibiletricicnipealissalcoaas 
Var. Greggii is larger and coarser in all its parts. The specimens before me are 1-2 inches 
in diameter ; tubercles 1-1} line long ; exterior spines 14-2 lines, interior stouter ones 4-1 
line long. The 6-9 upper elongated spines on the younger tubercles are 3-4 lines long, 
ret) at Py. : or more or less concatenat fluent 
leaving irregular pits in their interstices. Smooth or pitted seeds I find in most Minitarie ike Waddle veusaa 
: me Hei i the single Echinocactus setispinus, and all Echinocerei 
while the species of the other sections of Cereus known in our Flora generally have smooth seeds. OF the ‘quite peculiar large, 
flat, and bony seeds of Opuntia, I shall find occasion to speak hereafter. . he 
